History
A Troubled Past
The story of krill begins over 200 years ago, during the late 17th century. During this era, whaling became increasingly popular throughout parts of North America, Northern Europe, and some Asian countries. Whale oil and baleen were considered valuable commodities, especially in the wake of the Industrial Revolution. Primarily used to light lamps, it was also a high quality lubricant for machinery, one that would not corrode metal and became important for military instruments. The decrease in whale populations was expected to be met with a spike in krill populations, however the opposite result occurred.
The lack of whales meant a lack of whale excrement, a source of rich iron that is critical for the growth of phytoplankton. Therefore, phytoplankton suffered as well as their primary predator, krill. As the krill population suffered, so did the rest of the Southern Ocean food web. Most marine species feed on krill, and the decreased populations meant that all marine species suffered. The whaling industry sent cascading effects through the food web of the Southern Ocean causing consequences that are only worsening today.
Importance of Krill
Carbon Sink
Krill are playing an increasingly crucial role in mitigating climate change, sequestering large amounts of CO2 and aiding in its long-term storage. Krill are the largest carbon sink in the world, sequestering 13 billion tons of CO2 each year, equivalent to removing 35 million cars off the roads.
Krill's effectiveness as a carbon sink begins with their diet. Krill primarily eat phytoplankton, a tiny marine plant that absorbs CO2 during photosynthesis. Krill consume phytoplankton and capture the carbon into their own biomass, effectively removing atmospheric CO2.
What makes krill such a vital carbon sink is their role as a "conveyer belt" bringing the absorbed CO2 to the deep ocean, where it can be sequestered for centuries. Krill feed at night at the surface of the ocean and move to deeper waters during the day to evade predators. During these migrations, they release carbon-rich excrement into the deeper ocean layers, where it can remain stored for centuries.
Krill continue to sequester carbon beyond their life through their main predator; baleen whales. These whales consume massive amounts of krill to sustain their immense sizes and energy needs, effectively transferring the carbon stored in krill into their own bodies. In a single whale's lifetime, they are able to store the carbon equivalent to 1500 years. Once these whales die, their bodies sink to the bottom of the ocean carrying the carbon with them to be sequestered in the deep ocean.
In a world grappling with rising CO2 levels and the devastating impacts of climate change, krill's contribution to carbon capture and storage is invaluable. Protecting krill populations is not only vital for preserving marine ecosystems, but is essential in regulating the Earth's carbon balance and mitigating the effects of climate change. Krill are quietly helping to address one of the most significant challenges of our time and it is time we honor their importance.
Center of the Food Web
Krill are positioned in the center of the Antarctic food web, making them vital to the survival of an array of lifeforms.
Krill consume phytoplankton, a microscopic marine plant. Then, an array of creatures, from baleen whales to a number of species of fish, squid, and seabirds, depend heavily on krill as their primary food source. Next, larger mammals of the Antarctic, such as seals, penguins, and orcas depend on krill predators for their primary diet.
Krill's rich reserves of energy and nutrients are an important component to the ecosystems survival in the harsh climate of Antarctica. As climate change and human activities increasingly impact the Antarctic, it is crucial to recognize the central role of krill in the region and make the protection of krill a focal point in environmental conservation efforts.
Threat to Krill
Overfishing
The overfishing of krill is a concerning environmental issue driven by the rising demand for krill-oil products and the lack of robust regulations. Large-scale commercial fishing operations, particularly in the Southern Ocean closest to Antarctica, are intensively harvest krill, threatening the sustainability of these vital creatures.
The overfishing of krill is primarily because of its usage as an Omega-3 dietary supplement in North America, but it is crucial that alternative methods, which already exist today, immediately replace krill oil. The overfishing of krill disrupts a fragile food web and impacts the largest carbon sink on the planet. Overfishing of krill must be addressed quickly to ensure the health of marine ecosystems and the balance of our planet's carbon cycle.
